import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

public class ZipWriterExample {
    public static void main(String[] args) {
        String[] filesToZip = {"file1.txt", "file2.txt"};
        String zipFilePath = "output.zip";

        try (FileOutputStream fos = new FileOutputStream(zipFilePath);
             ZipOutputStream zos = new ZipOutputStream(fos)) {

            for (String file : filesToZip) {
                try (FileInputStream fis = new FileInputStream(file)) {
                    ZipEntry zipEntry = new ZipEntry(file);
                    zos.putNextEntry(zipEntry);

                    byte[] buffer = new byte[1024];
                    int len;
                    while ((len = fis.read(buffer)) > 0) {
                        zos.write(buffer, 0, len);
                    }
                    zos.closeEntry();
                }
            }
            System.out.println("ZIP-архив успешно создан: " + zipFilePath);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import java.util.Base64;

public class AESExample {
    public static void main(String[] args) throws Exception {
        // Генерация ключа
        KeyGenerator keyGen = KeyGenerator.getInstance("AES");
        keyGen.init(128); // 128-bit key
        SecretKey secretKey = keyGen.generateKey();

        // Шифрование
        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        String plainText = "Hello, World!";
        byte[] encryptedBytes = cipher.doFinal(plainText.getBytes());
        String encryptedText = Base64.getEncoder().encodeToString(encryptedBytes);
        System.out.println("Encrypted: " + encryptedText);

        // Дешифрование
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        byte[] decryptedBytes = cipher.doFinal(Base64.getDecoder().decode(encryptedText));
        String decryptedText = new String(decryptedBytes);
        System.out.println("Decrypted: " + decryptedText);
    }
}

public class Task190225 {
    public static void main(String[] args) {
        String dateStr = "2013-13-12 23:31:50";
        try {
            LocalDateTime date = LocalDateTime.parse(dateStr, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
            System.out.println(date);
        } catch (DateTimeParseException e) {
            throw new IllegalArgumentException("Ошибка парсинга");
        }
    }
}

import javax.crypto.Cipher;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.util.Base64;

public class RSAExample {
    public static void main(String[] args) throws Exception {
        // Генерация ключей
        KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA");
        keyGen.initialize(2048); // 2048-bit key
        KeyPair keyPair = keyGen.generateKeyPair();

        // Шифрование
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, keyPair.getPublic());
        String plainText = "Hello, World!";
        byte[] encryptedBytes = cipher.doFinal(plainText.getBytes());
        String encryptedText = Base64.getEncoder().encodeToString(encryptedBytes);
        System.out.println("Encrypted: " + encryptedText);

        // Дешифрование
        cipher.init(Cipher.DECRYPT_MODE, keyPair.getPrivate());
        byte[] decryptedBytes = cipher.doFinal(Base64.getDecoder().decode(encryptedText));
        String decryptedText = new String(decryptedBytes);
        System.out.println("Decrypted: " + decryptedText);
    }
}

import java.io.FileWriter;
import java.io.IOException;

public class Task200225 {
    public static void main(String[] args) {
        try (FileWriter writer = new FileWriter("output.txt")) {
            writer.write("Hello");
            writer.flush();
            writer.write(" World");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}